Syringe.



PATENTED FEB. 25, 1908.

J. WILSON.

SYRlNGB.

APFLIGATIGN FILED M1515, 1906.

UNrjrED STATES PATENT OFFICE JOHN wILSoNdOFBELMONT, MASSAGHUSETTS,ASSIGNORTO THE RANDALL-FAIOHNEY OOMPANY, or BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

sYRrNGE.

No.sso,433. v I

To all whom- 'it may:- vconcern:

' Be it known that I," JOHN WILSON, of Bcll mont, in thecountyof Middlesex and State of Massachusetts, have invented certain new and useful Improvements `in Syringes, of

which the following is aspecification.

This .invs'a'ntion relates 'to dental syringes,

and has .for its object, lfirst: to provide a syringe-ada ted to be conveniently charged vwith a'liqui to be expelled from the syringe,

and, secondly: to. provide means whereby a dental syringe may be operated'with greater ease and lessldiscomfort'to the operators hand than heretofore.

view of the syringe.

The invention consists'in the improvements which I now proceed to describe and claim. `1

Of the accompany drawings, forming a -part of this specificatiom-.Figure 1 re resents a longitudinal section of a syringe arrel embodying my invention, the piston being shown in elevation. Fig'. 2 represents an end The same letters of reference indicate the same parts in all the figures. z

The barrel of my improved syringe comprisesa body 'portion 12 havin a contracted delivering nozzle 13 at one en its other or upper end being reduced to form a Shoulder 14, and provided with anl external Screw thread 1 5. 16 represents a packing nut in. ternally screw threaded at one end to engage the thread 1 5, and provided with acompressible packing 17, closely fitting the piston 18. The outer end of the nut 16 is provided with a tapered throat 19. The chamber 20 of the barrel is of uniform diameter from the throat 19 to the ,nozzle 13, and the piston is correspondingly formed so that the piston can be entirel withdrawn from the barrelto per- .mit a iquid to be poured into the' chamber through the inner end of'the barrel. It will be Sleen that the taperedthroat 19 acts as a funnel to facilitate the introduction of liquid into therchamber.

Specification of Letters Patent. Ap'pimion nea nimma 190e.` sans No. 306.104.

nally threaded tls' Patented Feb. 25, 1908.

from opposite s ides of t e barrel, said rests be" preferably formed in a single piece, Whic includes a central a ertured portion 22, which is internally threa ed to engage the external thread 1'5, the said central portion being seated upon the shoulder '14 when in ace. p The piston is provided with a head 23,

. which is of elliptlcal form, and is rovided 21-21 vrepresent iingpr lrestsprojecting I erts pressure on the head, W1thout lbeing so Wide as to cause discomfort. Th-e, major axis of the elliptical head extends crosswise of the operators hand', so that the palm in closing on the head is curved across the shorter/I axis of the latter.

I claim: A syringe comprising a barrel having a body portion furnished with an external screw threadratts upper end, anut interandprovided with a tapered throat to facilitate the introduction of liquid into the barrel`,\ acking between the nut and the end of the bodyportion, and a piston adapted to be removed through 'the nut.

engage Said screw thread In testimony whereof I have affixed my I' signature, in presence of two witnesses. Y

. JOHN WILSON.` Witnesses:

' WILLIAM A. RANDALL, C, F. BROWN; 

